Cleaning soil contaminated with industrial chemicals, agricultural chemicals, oil and motor vehicle fuels has been recognized as a critical problem. Soils are often contaminated with hydrocarbons (such as oil and fuels), from slowly leaking storage tanks or from unintentional spills. Soils contaminated with lower molecular weight hydrocarbons have been treated by combusting the soil to remove the hydrocarbons to permit the cleaned soil to be re-used.
Other contamination is from hazardous materials, such as chlorine and more complex, higher molecular weight hydrocarbons, typically those above C30. The hazardous materials must often be incinerated at higher temperatures to break them down. However, the higher temperatures and the nature of the materials often create by-products which are themselves hazardous, so that combusting hazardous materials must be done very carefully. Generally, such systems designed for combusting hazardous materials include specialized exhaust gas scrubbers to remove any hazardous products of combustion.
One common way to treat contaminated soil is through the use of mobile systems, such as that used by Site Reclamation Systems, Inc. of Howey In The Hills, FL, Aztec Industries of Chattanuga, TN and General Combustion Company of Orlando, FL. One of the problems with mobile systems is that they make no provision for cleaning extraneous material in the soil. Often the rocks and other extraneous material are simply dumped back into the hole without treatment. The alternative is to truck the rocks and other extraneous material to a landfill. Thus, although the present mobile soil decontamination systems can and do help clean hydrocarbons from contaminated soils, they are necessarily limited in the range of materials which they can accommodate.